Motor control system



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H. E. HARTIG IOTOR "CONTROL SYSTEI Filed Get. 21. 1937 June 3.1941. l

o.. R VA Patented June 3, 1941 UNITEDf STATES .PATENT foFFicili 2,244,362 l y Moron conrnonsrsrm ,Y y Henry E. Hartig, Robbnsdale, Minn., assignor to f' f Minneapolis-Honeywell v- Minneapolis, Minn., a corporation of Delaware i e application october-21, 1931. serum .110,235 y. e comme. motoso-41.5) f f' e present invention is concerned with a motor control system. more particularly with one in which the motor is used to position an object remotely located from the controller.

An object of the present invention is to provide a system for remotely positioning an object in which a vlight beam is polarized with a predetermined angle of polarization and in which means responsive to the angle of polarization of the-light is e'ective to control the positioned object.

Further objects of the present invention will be apparent from a consideration of the accompanying specification, claims, and drawing oi which Figure 1 is a schematic view of one form oi my motor control system, and in which Figure 2 shows a portion oi a speciilc application of the control system. Referring to the drawing for a more detailed explanation, there is shown in Figure 1, in schematic form. the motor control system forming the subject of the prent invention. While it is to be understood that the particular invention is not limited to any particular object tov be positioned. this object has been shown in the drawing as a valve indicated by the reference numeral I6. This valve is varlably positioned by a proportioning motor generally indicated by the reference numeral il. The motor drives the valve through a shaft I2 to which is secured -a crank disc I3. A link Il is eccentrically connected to the crank disc I3 and is also connected to the stem oi valve It. Associated with the proportioning motor Il is a control potentiometer.,

. generally indicated by the reference numeral il. This control potentiometer comprises a resistance il and a contact arm 2U which is adapted to slidably engage resistance il. The contact arm is pivotally mounted at 2| to a suitable support 22. The vpotentiometer -Il is connected through conductors 2l, 25, and 2S to the pro- A portioning motor Il. The proportioning motor Il may be oi any suitable type wherein the motor assumes a position corresponding to the position of the controller. Thus when power is supplied to the motor H, the motor always as- Regnlator Company,

.mary 3i and a low v.voltage secondary 32. *The line voltage primary 3i is connected to line wir 33 and 34 leading to a suitable source ot power (not shown).

As indicated by the objects, 'the @animi m- .tem of .the present invention acts through the variation oi the angle of polarization of a beam ,of light. Any suitable source of light may .be

used. .In the present instance an electric lamp :Sis employed. the lamp being energized by any suitable source of power (not shown). Mounted .inthe path of the rays from the electric lamp Ais a disc of polarizing material. indicated hy the reference .character 31. This disais mounted upon a shait- 38 which is supported in bearings 39. The disc 3l may be of any suitable polarizing material, preferably of the substance known commercially as "Polaroid," which has the prop- .erty of polarizing any light which is transmitted therethrough. The angleoi the plane of polar- .ization can be. readily varied by rotating the disc. In order to rotate the disc 31, .the same .,ismounted in a rim n which is provided with teeth 4| on its under surface. Cooperating with .the teeth is a knob which is provided with teeth 43 around the upper portion of its periphery. 4Knob.42 is provided with a.pointer u which cooperates 'with a scale 45. It will be. readily understood that by rotation o! the knob A2 the. angular position oi the polarizing disc 31 may be varied andin consequence the angie oi polarization is accordingly varied. The pointer 4I and scale I5 provide a convenient means oi indicating the degree oi' angularity of the po-- larined disc 31. It is to be understood that the` scale may be calibrated to any suitable units depending upon' the speciiic application of the system. Thus i! valve I! is employed in a heating system, wherein it controls the iiow of steam' or other similar heating iluid, the scale 8 may be calibrated in terms of steam new, or in some instances, in terms oi' degrees of temperature.

sumes a position corresponding to the position of the potentiometer arm 2l. Such an arrange- A step-down transformer 3B is used to supply g. power for operation oi the motor H and for op-- eration oi the motor control system generally.

Intel-posed between the disc I1 of polarizing material and the source of-light 8S is a lens 41 which serva to direct the-rays along substantially parallel lines through the disc l1. In this manner, the diversion of the light rays is decreased. positioned is a receiving disc I! of polarizing material, preferably o! the same type as used ,indlscll Thiadlscisecuredtolahaftll which a supported in bearings u ma sz. -Tne disclsdisposedinthepathoithelishtrlyl .This transiormer comprises a line voltage pri- 81. Also mounted in the path oi the iight raya Located adjacent to the-obiect to be v after they have passed through the second polarizing disc (l is a photoelectric cell 54. Interposed between the disc I8 and the electric cell 54 is a lens 55 which serves to converge the light rays upon the photo-electric cell.

As is well known, a member of polarizing ma terial will pass polarized light only when it is disposed in an angular position corresponding to the plane of polarization of the light. This oction is quite critical. If a disc of polarizing materia] is held in front of a polarized light beam,

the light will not pass through the disc o! polarlzing material to any substantial degree until the angular position of the disc almost. identically coincides with the angle of polarization of the light, under which condition the light will be transmitted through the polarizing disc with almost full intensity. Referring to the specific apparatus, it will be clear that substantially no light will be received by the photo-electric cell 5l until the angular position of disc IS substan tially coincides with the angular position of disc 31. In order to change the angular position of disc i9, the shaft 50 is driven by a motor i1 through a reduction gear train 58. 'I'he shaft 50 and consequently the disc 49 is rotated continuously in the direction of the arrow adjacent disc 49. Also secured upon shaft 50 are a pair oi' switch cams 58 and 60. Cam 59 is adapted to cooperate with a switch blade 6|` which, in turn, is adapted to be moved into engagement with a contact 62. .'I'he cam 58 is provided with l. toe. portion $3 which upon engaging the cam follower of switch blade 6i causes the same to move into engagement with contact 62. The cam is adapted to cooperate with switch blade 6l, which in turn is adapted to engage a contact $5. The cam $0 is provided with an elongated raised portion B6 which upon engaging the cam follower of switch blade 6I causes the same to be moved into engagrnent with contact i against the bias of blade arm 88 to be moved out of the path of arm Il. Y

When the electromagnet is deenergized, a spring 93 is elfective tosmove collar 8 6 towards the right so that arm 88 is in the path of arm 88.

. Ihe energization of the electromagnet Il is controlled by the photo-electric cell 54 through f a suitable ampliiier 95. The photo-electric oeil is connected to the amplifier by conductors l5 and 91. Power is supplied to the amplifier 95 from the'secondary 32 through conductors 8l,

99, |00, and li.' The output terminals ,|03 and IM of the amplifier S5 are connected to the electromagnet winding S2 by conductors IUS and i". It will be understood that whenever the angular positions oi discs 31 and 49 coincide, light will be received by photo-electric cell 54, which when amplified causes the energization of the electromagnet and consequent disengagement of the 'clutch-II.

The switch consisting of switch blades Il and 65 controls the energization of the proportioning motor il. During certain periods oi' the operation, power is supplied to the proportioning motor and when this is done, the position taken by the motor is determined by thn then position of arm 2li. During the times that the switch blade Il is separated from contact i5, thus removing power from the proportioning motor Il, the position of arm 20 of potentiometer IB has no eifect on the proportioning motor I i and the valve Il remains in the position to which it was last moved by the motor.

Driven by shaft 50. at certain times in the op eration of the system, is a second shaft 1l, which shaft is supported by suitable bearings 1| and 12. Secured to shaft 10 is a disc 13 which has secured thereto a pulley member 1I. Secured to the pulley member 14 is a cable or other similar device 15, which is secured at its lower end to the potentiometer arm 20. A spring 16 is also secured to arm 20, being secured at its lower end to a rigid support 11. When shaft 1I is rotated in a clockwise direction, the cable 15 is wound u p on pulley 14 and moves arm 20 upwardly along the resistance I8 against the biasing action of spring 16. Located along the outer periphery of disc 13 are ratchet teeth 1l which cooperate with a pawl member 1l secured to a solenoid core Il.

e Cooperating with the solenoid core 80 is a solenoid winding 8|, which when energized moves core 8U and consequently pawl member 1! out of engagement with the ratchet teeth 1I. As will be more apparent from-the accompanying descrlption. the switch consisting of switch blades Il and $2 controls the energization of solenoid Il.

As indicated earlier the shaft is operative during certain portions o! the operation to drive operation of Figure 1 f" The various elements in this system are shown in the position they occupy at the beginning d the cycle wherein shaft 1li is rotated by shaft 5l. In this position the clutch 85 is engaged, the sol noid winding Il is deenergized so that pawl 1l engages the ratchet teeth 18. and switch' N is disengaged from contact B5 so that no power il supplied to the proportioning motor il. The notation of shaft 50 in a clockwise direction, under these circumstances, will cause a clockwise rotation of shaft 1U and a clockwise rotation of disc 1I. .This rotation'o! disc 13 is eil'ective to wind the ble 15 upon the pulley 14 and to move arm 2| upwardly of the resistance as previously explained. All during this movement of arm 2l. it exerts no control whatsoever over proportioning Y motor Ii due to de-energization of the latter. When the disc I! reaches a position corresponding to that of disc $1 so that the light polarized by disc 81 is able to pass through disc II, the photo- ,v

electric. cell 5l is illuminated and the current passed thereby is ampliiled through amplifier Il to cause energization of the electromagnet winding $2 so as to disengage the clutch IS. vA1- y though this disengagement o! clutch II courtinues onLv so long as the photo-electric cell il shaft 1I. A magnetic clutch, generally indicated .by the reference character 85, serves to control the connection between the shafts 5I and 1I. This clutch consists of a collar member I8 which is slidably secured to shaft i.. The' collar Il is held against rotation on shaft 5U by a spline l1. Collar Il is provided with a projecting arm Il fact that the pawl 1l prevents reverse rotation .f'

is illuminated, it will continue sumciently long to allowarmlltopassthearm. Inviewoftlaes` of shaft 1I, the position oi' shaft 1l will remain fixed anni solenoid winding u is eenmaal Consequently, in spite o( the fact that collar is subsequently allowed to'move back to the right upon deenergimtion ofthe electromagnet, the which is adapted to engage an arm 'Il secured 75 rotation oi' shait 8l will have no eifect position of shaft 'it until arm 88 again engages arm 89, which will be at the end of the cycle.

After the shaft 50 has completed substantially 180 of rotation, the cam follower of switch 64 engages the raised portion 65 of cam 6D causing switch blade 64 to be moved into engagement with contact S5. When this takes place, the power is supplied to proportioning motor II through 4 the following circuit: from secondary 32 through conductors 98 and III), switch blade 64, contact 65, conductor motor I|, and conductor II2 to the other terminal of secondary 32. As soon as power is supplied' to the motor in this manner. the motor starts to move to assume the position corresponding to the position of arm 20. if it does not already assume such a position. The raised portion EG of cam 8D extends throughout over 120 of the cam surface and the speed of rotation of cam 60 is sumciently slow so that during the time required for the cam 60 to move through this amount oi its rotation, the motor is able to move valve I to the position corresponding to a position of arm 20.

Shortly after the cam follower of switch blade 64 passes ou the raised portion S5 of cam 60, the toe 63 of cam 59 engages the cam follower of switch blade and causes the latter to engage used tor maintaining -constant the concentration Itiswellknownthatasugar solution has the property of rotating the plane ,I of polarization of polarized light passed therethrough. By transmitting the light polarized by disc 3l through a sugar solution and causing thel. Vposition of a. controlled valve to be varied in ac-Y f' cordance with the amount of rotation of the plane of polarization of the light and its passage 'E through the sugar solution, it is possible by emoi' a sugar solution.

ploying the valve to control the concentration of the sugar solution to maintain s. substantially the apparatus have been indicated by corresponding reference numerals in the two figures. In

l. constant concentration. The similar elements o! l *I this species as in the preceding species. a lamp i 35 constitutes the source of light and the light furnished thereby is passed through a lens 41 to contact $2. When this happens, an energizing circuit is established to solenoid winding 8| as iollows: from secondary 32 through conductors 8B,

|III, and ||5, switch blade 6|, contact 62, conductor IIB, solenoid winding 8| and conductors I|`| and ||i| to the other terminal of secondary 32. As soon as this circuit is established, the winding 8| is energized, which as previously explained. causes pawl l! to be moved upwardly out of engagement with the ratchet teeth 1I. When this occurs spring 1S is eiectivc to rotate disc 'i4 'and consequently shaft 'i0 in l. counterclockwise direction, at the same time moving potentiometer arm 2D downwardly. Tins downward movement continues until arm I! engages shaft 8B. permit the return of disc Il to the starting position, switch 6| moves out of engagement with the toe portion 63 of cam 58 so as to separate from contact B2 and open the circuit to solenoid winding l I. When this occurs the elements are again in the position shown in the drawing, whereupon the cycle is repeated.

It is to be understood that the knob 42 is actuated whenever it is desired to change the position of valve I0. By changing the position of knob 42, the' angular position of disc 31 is changed; 'I'his in turn results in a change in the angular position of `dise 49 at which light is passed to the photo-electric cell 54 to etiect the After suiiicient time has elapsed to disc 3l of suitable polarizing material such. asl

Polaroid A knob 42 issimilarly provided. f or adjusting the angular position of the polarized disc 3l. In this case, the scale 45 with which the pointer 4.4 of knob 42 cooperates, is cali rated in units'of concentration of the sugar solution.

The sugar solution is contained in a receptacle |50 which is provided with windows ISI and i52. The polarized light transmitted through disc I1 passes through window ISI, the sugar solution |54 in the receptacle |50, and the window |52 to the second polarized disc 49. When the angular position of disc 49 corresponds to the angle of the plane of the polarization of the light leaving the sugar solution, the light passes through disc 49 and lens 55 vto the photo-electric cell 54. The

valve I0, in this species, is employed to control the flow of water through a pipe |55 into a receptacle |53. A pipe |56 also leads into the rcceptacle |50, this pipe leading from l. container of a relatively concentrated sugarsolution. Connected to the upper end of container |58 is anoutlet pipe |51 which serves to convey the sugar solution away to a suitable point of storage or utilization. The concentrated sugar Vilowl through pipe |58 at a more or less uniform rate So that by suitable variation of the valve Il. which controls the flow of water to the solution,

it is possible to vary the concentration of the solution |54.

rn the operation of this system the knob u is turned to a point corresponding -to the desired concentration of sugar. 'I'he apparatus is initially adjusted so that with this setting of knob 42 and consequently disc 31, the position assumed by valve III, as e. result of the control exerted thereon by disc 45 will be such that lust enough l vwater is passed to the container |50 to maintain disengagement of clutch 85 and to thus termithe intermediate medium.

specianfnourez In Figure 2 there i's-shown an application of the l' present system wherein `it finds particular utility. In the arrangementA oi'Figure 2, the system is the concentration of the sugar solution |54 at the desired value. As soon as the sugar solution changes in concentration, the angle of rotation of the plane of polarization caused by the light passing through this solution |54 will be changed so as to cause a corresponding change in the position of valve I0. This change in the position o1.

valve I|I will cause more or less water, as needed.

to he supplied to the solution |54 to restore the concentration to the desired value.

It will be seen that I have provided an appara tus for remotely controlling an object which is ideally adapted to the situation wherein the n mately controlled object is in a location where it is undesirable to extend wires to the controller and the controlled oblect. It will also be leen that this system has the advantage that it doel not depend upon the intensity o! a light beambut rather solely upon the rotationLV of the plane o! polarization which is unatlected by normal transmitting mediums such as air. It will iurther be seen that the system in question is ideally adapted to the control oi the constituency of a medium which varies the angle of polarization 5 o! polarized light in accordance with'the oonstituency thereof.

While I have shown a speciiic embodiment of my invention for the purpose oi illustration. it is to be understood that the invention is limited only l by the scope of the appended claims.

I claim as my invention:

1. In combination, an object to be positioned. motor means for positioning the same. a source of light, means ior polarizingsaid light, means l for varying the angie of polarization, and means responsive to the angle o! polarization of said light for controlling said motor means and operative t-c cause the same to drive said object to a position proportional the angie 0I polariza- 20 tion of the light. Y

2. In combination, an object to be positioned,

motor means for positioning the same, a, source of light, means lor poiarizingsaid light, means for varying the angleoi polarization, means in the path of said polarized light capable oi' passing said light only when disposed at an angle corresponding to the angle of polarization of said light. means for changing the angular position of said last named means until it passes light, and

means controlling said motor means to cause the same to drive said object to a position corresponding to the position of said means in the path of the polarized light.

3. In combination. an object to be positioned,

motor means for positioning the same. a source of light, a member of polarizing material located in the path oi said light, means for varying the angular position of said member, and means responsive to the angie of polarization of the light 0 passingl throught said member Ior controlling said motor means and operative to cause the same to drive said object to a position proportional to the angular position of said member.

4. In combinatiom-an object to be positioned,

A:member of polarizingmaterial located in the path .l

ci iight polarized by'said first member. means i'or changing the angular position oi said last-named member until the polarized light is passed by said member. and means controlling said motor means to cause the same to drive said object to a position corresponding to the position oi said second member of poiarizable material.

5. Incombination, an object to be positioned. motor means ior positioning the same, a sourceof light, a member of polarizing material located in the path oi said light. means for varying the angular position oi said first member, a second member of polarizing material located in the path oi the light polarized by said mst member, means for changing the angular position of said last named member, a controller, means operatively connecting said controller and said last named member of polarizable material until the polarized iight is passed by said member, means,` operative thereupon to render said connecting means ineffective. and means associated with said third mentioned means operative subsequent to the disconnection of said connecting means to cause said motor means to move said object to l position corresponding to the position of said controller.

6. In combination, an object to be positioned, motor means for positioning the same. a -aouree o! light, a member oi polarizing material located in the path oi said light. means for varying the angular position oi said nrst member, a second member oi polarizing material located in the path oi the light polarized by said rst member. means for continuously changing the angular position of said last named member. a controller, means effective to periodically operatively connect said controller and said last named member of polarizable material until the polarized iight is passed by said member, means operative thereupon to render said connecting means inetfective. and means associated with said third mentioned means operative during periods following said periods of operative connection between said controller and said second named member o! polarizable material to move said object to l. pod tion corresponding to the position o! said controller.

HENRY E. Hilario.l 

